Re: Performance of full outer join in 8.3

I wrote:
> =?ISO-8859-1?Q?Christian_Schr=F6der?= <cs@deriva.de> writes:
>> This is the query:
>> select isin from ts_frontend.attachment_isins full OUTER JOIN
>> ts_frontend.rec_isins using (attachment,isin)  WHERE attachment=2698120
>> GROUP BY isin limit 1000;

> Hmm.  It seems 8.3 is failing to push the attachment=2698120 condition
> down to the input relations.  Not sure why.  All that code got massively
> rewritten in 8.3, but I thought it still understood about pushing
> equalities through a full join ...

I've applied a patch for this.  It will be in 8.3.8, or if you're
in a hurry you can grab it from our CVS server or here:

http://archives.postgresql.org/message-id/20090416204228.579317540E2@cvs.postgresql.org

            regards, tom lane